Installd: Do not log on missing B artifact

For now, just swallow the warning.

Bug: 25612095
Change-Id: Ib7131464c7eb85c153cb91bf5ff9dc2a6127dd4c
diff --git a/cmds/installd/commands.cpp b/cmds/installd/commands.cpp
index ac2ee30..15c1036 100644
--- a/cmds/installd/commands.cpp
+++ b/cmds/installd/commands.cpp
@@ -1852,7 +1852,8 @@
     {
         struct stat s;
         if (stat(b_path.c_str(), &s) != 0) {
-            LOG(ERROR) << "Can't find A/B artifact at " << b_path;
+            // Silently ignore for now. The service calling this isn't smart enough to understand
+            // lack of artifacts at the moment.
             return -1;
         }
         if (!S_ISREG(s.st_mode)) {